In order to improve the safety, detection equipment is applied to detect trace substances attached to a detected object, and in order to cooperate with the detection, a sample collecting and introducing device is applied to collect and extract samples attached to the detected object.
At present, there are a variety of sample collecting and introducing devices. As one of them, the sample collecting and introducing device comprises a sampling device and a semipermeable membrane device, wherein the sampling device sweeps the detected object via airflow to collect samples and conveys the collected samples to the semipermeable membrane device through an air guide cavity, and the semipermeable membrane device extracts the samples via a semipermeable membrane and conveys the extracted samples to the detection equipment for detection. As the samples are extracted by the semipermeable membrane, not only the instrument contamination can be prevented, but also an enrichment function can be played on the samples to improve the sampling efficiency. The larger the area of the semipermeable membrane is, the more favorable to improve the sampling efficiency it is.
However, in the prior art, the semipermeable membrane is usually arranged inside the sampling device. In this case, to increase the area of the semipermeable membrane, the size of a structural component of the sampling device outside of the semipermeable membrane has to be increased accordingly, which is difficult, and increases the weight and the volume of the entire sample collecting and introducing device, thus making the sample collecting and introducing device inconvenient to use.